Strain insulator clevis



Sept. 23, 1941. `.1. B. cooK Patented Sept. 23, 1941 STRAIN INSULA'roR lcLEvis .John Brown Cook, Chicago, Ill., assignor to Reliable Electric Company, Chicago, Ill., a corporation of Illinois Application September 18, 1939, Serial No. 295,475

4 Claims.

The present invention relates to means for anchoring a strain insulator or the like to a mechanical load carrying member such as a cross arm of a transmission pole. It is particularly concerned with what sometimes is called in the Ytrade a dead end strain insulator clevis. My improved clevis utilizes a tension member adapted to be threaded through a strain insulator or similar device attached to the wire or cable sought to be anchored. 'I'he tension member is provided at its ends with heads designed to enter into engagement with a cooperating device which is mounted on the load carrying member. The present invention contemplates a cooperating device which 'provides for ready attachment and release of the headed tension member, herein- 'after referred to as a wire, without disturbing the mounting of the device. Preferably, said device comprises spaced slotted portions extending away from the load carrying membery on which it is mounted with anges on said portions provided with slots to receive 'the wire and to prevent passage of the heads of the wire. The strain from the strain insulator or the like is carried by the length of wire to the heads thereof and is transferred to the anchoring device by means of the heads bearing on the anges.

The purpose of the present invention is to pro- `vide an improved connecting device between the 'strain insulator or the like and the load carrying member. it is desirable to minimize the number of parts necessary in la device of this character and to provide means for hooking the length of wire in place after the clevis is mounted in position. This latter feature permits replacement of the strain insulator without having to remove the clevis and any other equipment mounted at the other` end of the bolt fixing the clevis to the cross arm or load carrying member. it is also desirable to provide a latitude in the angle of take-oid that the device will accommodate and yet 'retain the maximum load carrying strength. Applicants invention provides these features and advantages in a device characterized by simplicity and ease of manufacture.

'The features and Yadvantages of the present invention will appear more fully as the description proceeds, reference being had to the accompanying drawing wherein a preferred form of the invention is shown. It is to be understood, however, that the drawing and description are illustrative only, and are not to be taken as limiting the invention except insofar as it is limited by the claims.

In the drawing,

vlength of wire I3 in any suitable fashion. In the .F.ig. 1 is .a side elevation illustrating the clevis assembly connecting a dead end clamp and strain insulator to a cross arm;

Fig. 2 is ar top view of the clevis assembly showing the method of connecting the lengthv of Wire to the clevis;

Fig. .3 isa view showing the slotted anges, arid Fig. 4 is .a view illustrati-ng the mounted clevis showing a large take-off angle.

Referring now in detail to the drawing, the present invention'is directed toward a dead end strain insulator clevis by which a wire or cable i5 may be anchored to a load carrying member 2i. `In carrying ,out the present invention, the wire I'I is gripped in a dead end clamping device II which is threaded through a strain insulator or the like I2. Also threaded through the strain insulator -or the like SI2 is a length or strand of wire or other suitable material I3, the ends of which are provided with heads I4 and I5. The heads I5 and I5 are of such size that they may be readily threaded through the openings 34 and 35 provided in the clevis memberashereinafter described, Y

The heads ,Ifl 'and I5 may be provided on the present 'invention they are-shown as tubes of metal which are compressed on the wire I3 by applying pressure to the opposite sidesthereof at points i6 and Il by which the metal of the tube is forced inwardly to deform the wire 'I3 and thus permanently unite the tubes I4 and I5with the wire I3.

To receive and hold the wire -I3 a cooperating device 20 is provided. 4'Said cooperating .device 26 is mounted on the load carrying member EI', which is shown in the drawing as a cross arm iixed to a pole 22. In the preferred embodiment of the invention, the cooperating device 20 is mounted on the load carrying member 2l by means of a bolt 23 passing through a hole 24 in the cooperating ndevice 2'@ and a hole through the member 2l- The bolt `23 is fitted with a nut '25. Extending away from the portion of the cooperating device v20 adjacent tothe load carrying member 2i are spaced portions 30 and 3l, and extending therefrom are curved iianges 32 and 33.

The spaced portions 30 and 3I are provided with slots or openings 34 and 35 somewhat removed from the flanges 32 and 33. Said slots or openings 34 and 35 are of an appropriate size to permit the heads I4 and I5 on the wire I3 to readily pass therethrough. Extending away from the slots 34 and 35 are slots 3B and 31. Said slots 36 and 3T extend into the flanges 32 and 33, respectively, and are of a Width to permit the passage of the wire I3. Connecting to slots 33 and 37 in the flanges 32 and 33 are slots 38 and A 39. Said slots 38 and 33 extend throughout a portion of the length of the flanges 32 and 33 and are of a width sufficient to permit the passage of the Wire I3 and to refuse passage to the heads I4 and I5 on theWire I3.

To assemble the length of Wire I3 with the cooperating device 23, heads I4 and I5 on the wire I3 are respectively passed through the slots 34 and 35 in the spaced portions 30 and 3|, At

the same time, the wire I3 enters the slots 38 and 39 in the flanges 32 and 33 through the connecting slots 36 and 3l. As thus assembled, the heads I4 and I5 bear on the flanges 32 and 33, the Wire i3 passing through the slots 38 and 39 and around the strain insulator I2.

It is to be noted particularly that in the principal form of the invention the flanges 32 and 33 are longitudinally curved throughout their length. The purpose of this curve is two-fold. The slots 33 and 31 entering the flanges 32 and 33 are so related to the curve that the portion of the ange at the slots 36 and 3'I will never be used for bearing surfaces for the heads I4 and I5. This construction permits a maximum bearing surface for the heads I4 and I5, regardless of the position of the Wire I3 in the slots 33 and 39. In other words, the portions of the flanges weakened by the entrance slots 33 and 31 will never be used for bearing. The curve of the slotted .flanges 32 and 33 permits the use of any angle of take-off within the limit set by the degree of curve and length of the flange. The maximum strength of the device is maintained at any angle of take-off as the heads I4 and I5 bear fully on the flange regardless of the angle used.

As a variation of the above described form of the invention, it may be desirable to provide the means for attaching or detaching the length of Wire at one of its ends only. This could be accomplished by, for example, eliminating slot 34 and slot 36 from the spaced portion 3U. The wire I3 Would necessarily be threaded through slot 33 before the heads I4 and I5 Were fixed on the wire.

It Will be readily apparent from the foregoing description that I have provided a simple, economical and highly convenient clevis of the character described.

From the foregoing description it is believed that the construction and operation of the prestherein communicating with the slots n said spaced portions, the slots in said spaced portions being of appropriate size to permit passage of the enlarged heads of the Wire therethrough, the slots in said flanges being of a Width greater than the diameter of the Wire but less than the Width of the heads at the ends thereof, said flanges being longitudinally curved substantially throughouttheir length so the takeoi angle of the Wire can be changed.

2. A clevis of the character described comprising a tension member having enlarged heads at both ends, a mounting device for said tension member comprising a substantially flat base and spaced, substantially parallel, plate portions projecting from said base, curved flanges at the free edges of said parallel portions opposite the base, said flanges extending substantially at right angles to said spaced portions, said parallel portions having slots large enough to receive said heads extending toward said flanges, and said flanges having slots running lengthwise thereof along the curve, the last named slots being too small for the heads and large enough to receive the tension member, one end of each of the flange slots being connected to the enlarged slots in said spaced portions by an intermediate slot large enough to pass the tension member but too small for the heads thereon.

3. A clevis comprising a mountable member including a web portion adapted to be secured to a' load carrying member, spaced tension member attaching portions extending in the same general direction from said web, a tension member, at least one of said portions having a lateral flange extending from the free end thereof, said ent device will be readily apparent to those skilled portion and said flange having slots therethrough, and a slot connecting the slot in the flange to the slot in the spaced portion, the slot in the ange extending lengthwise thereof in spaced relation to the adjacent wall of the portion to which it is attached and being spaced from the free edge of said flange throughout its extent, said tension member having an enlarged head, the slot in said spaced portion being sufficiently large to pass the enlarged head on said tension member, the slot in said flange and the connecting slot being sufficiently large to pass the tension member, but too small for the head thereon.

4. A clevis comprising a mountable member including a web portion adapted to be secured to a load carrying member, spaced portions extending in the same direction from said web, at leastd one of said portions having a slot therethrough, lateral longitudinally curved flanges extending f fromthe free ends of said spaced portions, said 

